1) Take a skillet and add the onion into the oil
2) Cook the onion for 6 minutes to make it soft.
3) Add garlic to the onion and cook for another 2 minutes.
4) Add tomatoes, parsley along with salt and pepper.
5) Cover the skillet and simmer on low heat for 10 minutes.
6) Now put the mixture into the container of a food processor. Puree the mixture.
7) Put the tuna to the blender and puree it.
8) Add the broth to make a thick sauce.
9) Meanwhile, cook the rotelle in a pot of boiling water.
10) Drain the rotelle and toss it with sauce.